Traditionally, chlorofluorocarbons (CFCs) like trichlorofluoromethane and dichlorodifluoromethane have been used as refrigerants, blowing agents and diluents for gaseous sterilization. In recent years, there has been universal concern that completely halogenated chlorofluorocarbons might be detrimental to the Earth's ozone layer. Therefore, stratospherically safer alternatives to these materials are desirable.
There is presently a worldwide effort to use fluorine-substituted hydrocarbons which contain fewer or no chlorine substituents. The production of HFCs, i.e. compounds containing only carbon, hydrogen and fluorine, has been the subject of interest to provide environmentally desirable products that could provide a substitute to CFCs. Such compounds are known in the art to be produced by reacting hydrogen fluoride with various hydrochlorocarbon compounds. While HFCs are considered to be much more environmentally advantageous than hydrochlorofluorocarbons (HCFCs) or chlorofluorocarbons (CFCs) because they are not non-ozone depleting, recent data indicates that they may also contribute to greenhouse global warming. Accordingly, alternatives to HFCs, HCFCs, and CFCs are also being explored.
Hydrofluoroolefins (“HFOs”) have been proposed as possible replacements. It is generally known that HFOs are best used as a single component fluid or azeotropic mixture, neither of which fractionate upon boiling and evaporation. The identification of such compositions is difficult due, at least in part, to the relative unpredictability of azeotrope formation. Therefore, industry is continually seeking new HFO-based mixtures that are acceptable and environmentally safer substitutes for CFCs, HCFCs, and HFCs. This invention satisfies these needs among others.